Greece is in big trouble. Tuesday is when the country is supposed to pay back a huge loan it received to pay off debt from a few years back. Why is Greece in this mess? Greece piled up debt by spending way beyond its means. To make matters worse, the country has a retirement age of 57, which is good for workers, but a huge burden for the government when it comes to paying out benefits. Who does Greece have to pay back? First, Athens borrowed billions from European banks to make ends meet. But then it couldn't pay back those loans. So in 2010, it got a bailout from the European Central Bank, the International Monetary Fund and the European Commission to pay back the banks. Now, it has to pay back the bailout. Why is it having trouble paying? Most of the bailout money Greece received was to repay the initial creditors, not to help get the country on good footing. So when Greece didn't solve its underlying problem of an under-performing economy, things just kept getting worse. How bad is it right now? If Greece doesn't pay back the loan, it faces the prospect of default. The country closed its banks starting Monday, imposed limits on cash withdrawals and closed its stock market. What would a default mean? Greece might have to leave the eurozone, which means it wouldn't be able to use the euro anymore and would have to issue its own currency (and it's not certain people would accept it). Jobs will be harder to come by. Government services will become scarce. Basically, bad news all around. How could Greece's woes affect Europe's economy? Opinions differ. Some say there's a big unknown risk. Others say it's really Greece's problem, and the eurozone would be just fine without the country. U.S. stocks. They're buckling but not breaking. One more thing. Greece isn't the only place with big financial troubles this week. Puerto Rico is just days away from a historic economic collapse after the commonwealth's governor said the U.S. territory can't pay its $72 billion in debts.

And this year's rulings will have major implications for how we live, die, work, vote and love. If you want to dive into all the decisions from this term, check out our interactive. Here's what came down Monday, the final day of rulings: EPA clean-air regulations. The justices shot them down. The co...